The present invention relates generally to gas pressure regulator valves and more particularly to an improved gas flow rate control regulator valve for maintaining an optimum precombustion air to gas ratio for a wide range of air and gas flows within the combustion chamber of a furnace for efficient burning therewithin. Several exemplary embodiments of the present invention are disclosed hereinbelow.
To accomplish efficient combustion of gaseous fuels, an optimum air to fuel mass ratio must be maintained over a wide range of air and fuel flow in the system. If air and fuel gas temperatures are similar the optimum ratio may be achieved simply by mechanically linked air and gas valves.
To achieve further efficiency, however, energy in combustion by-products must be utilized to heat combustion air prior to combustion, and thereby recuperate a portion of the heat usually wasted. When air is heated without volume constraints, it expands, becoming less dense, and therefore has low mass per unit volume. When mechanically linked air and fuel valves are used, varying combustion air temperatures will change the air to fuel ratio from optimum, since fuel gas temperature is usually in the ambient range.
To solve these and other problems, the prior art teaches a wide variety of regulator valve mechanisms. Many of the prior art mechanisms include devices which will function over only a narrow range of air and gas flows. Additionally, many such prior art devices have the further disadvantages of inaccuracy during use, undependability in the field, necessitation of frequent maintenance, and complexity of structure leading to increased initial expense.
In addition, many such prior art regulator valves for mechanisms have required excessively lengthy dimensions because of the multiplicity of the various parts necessary to insure accuracy and dependability, and in some cases such excessive dimensions have prevented the utilization of the devices in circumstances wherein there was insufficient space.